CI enforces forge fmt with a pinned Foundry version (v1.3.6) so formatting is
reproducible regardless of your local Foundry. Before committing:
make fmt # format using the pinned version
make fmt-check # verify (identical to the CI check)make fmt installs Foundry v1.3.6 side-by-side on first run — it does not have to be
your default. The initial install switches your active Foundry to v1.3.6; run
foundryup -u stable to switch back.